JPS5980150A - Linear pulse motor - Google Patents

Abstract

PURPOSE:To be adapted for a small thrust and a small stroke in a linear pulse motor by forming a direction of a magnetic flux generated at the primary side body when passing in the pole and a direction when passing the pole surface and between teeth parts formed on the scale surface opposed to the pole surface at a right angle. CONSTITUTION:The primary side 17 of a linear pulse motor is composed of cores 18, 19, permanent magnets P1, P2 for coupling the both sides of the cores, poles 20-23 extending perpendicularly from the opposed surface of the cores 18, 19, and exciting coils 24-27 respectively mounted on the poles 20-23. In this case, the pole surfaces 20a-23a of the poles 20-23 are determined in a direction at 90 deg. from the direction extending at the poles 20-23 from the pole mounting surfaces of the cores 18, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention particularly relates to the basic configuration of a linear pulse motor that is small and has a small maximum displacement on the movable side.

Generally, a linear pulse motor displaces the movable side in steps by a fixed distance for each input pulse supplied to the primary coil. Along with this operation, linear pulse motors are applied to head feeding of various printers that require accurate positioning control, head feeding of photoelectric reading devices, and the like. Specific examples of conventionally commonly used linear pulse motors are as shown in Figs. In the side views, 1 is the linear pulse smoke primary side, two cores 2 and 3 are magnetically cut off at the center of the front, and side plates 4 fix each core 2 and 3 on both sides. ,5
, permanent magnets 6, 7 magnetized with the polarities shown on the back of each of the iron cores 2, 3, and the permanent magnet 6. '7 magnetic plate 8. Coils 9a to 9 (1, shaft 10.1111'n rotation supported under both sides of each side plate 4, 5) attached to magnetic poles 2a, 2b, 3a, 3b formed on each of the above iron cores 2.3 Wheels 12 that are freely supported
It consists of 15 parts. And each of the above magnetic poles 2a, 2b
, 3a, and 3b, 2al, 2bl, 3al, and 3bl are formed with a shift of 1/4 pitch. 16 is a scale forming the secondary side of the linear pulse motor, and the above-mentioned magnetic pole teeth 2al, 2bl, 3a are shown on the plane.
Teeth portions 16a are formed with the same pitch as those of teeth 1 and 3bl.

In the linear pulse motor shown in FIGS. 1 and 2 above, when driving, for example, by the -phase excitation method, each coil 9a is
~9d In the process of excitation, each magnetic pole 2a, 2b
, tooth portions 2al and 2b formed on 3a and 3b,
3al and 3bl sequentially oppose the teeth of the secondary scale, thereby stepping forward by 1/4 pitch (in the actual operation process, it appears to be a continuous operation). On this occasion.

The primary main body 1 and the secondary scale 16 are put into practical use by fixing one and moving the other.

Incidentally, in recent years, with the development of office automation equipment, there has been a strong trend toward smaller and thinner information terminal equipment, and this trend is also becoming stronger in floppy disk drives, for example. Due to such market demands, compact and ultra-thin linear pulse motors are required.

Currently, the trolley-type linear pulse motor shown in FIGS. 1 and 2 cannot meet the above-mentioned market demands. In other words, in the above-mentioned floppy disk drive, etc., the thrust is usually about 10 to 10 logs and the stroke is about 10 to 30 logs, whereas the conventional trolley type linear pulse smoker has a large thickness even for the purpose of miniaturization. There is a limit to the reduction of W in order to obtain the minimum strength of the wheel mounting mechanism, and the height H
It is difficult to reduce b in the conventional structure shown in FIG. 1.2 above, in which the primary and secondary teeth facing surfaces are perpendicular to the magnetic flux passing through the magnetic pole. On the other hand, there is a limit to the shortening of the length L based on the necessity of arranging the magnetic poles in the moving direction of the linear pulse motor movable side.

The purpose of this invention is to provide a linear pulse motor that uses the same driving principle based on the characteristics of the configuration of the primary side of the linear pulse motor, but is miniaturized to suit low thrust and short stroke characteristics. be.

The illustrated embodiment will be specifically described below. 1st
The figure shows a plan view, FIG. 2 shows a front view, and FIG. Magnetized permanent magnet P1↓P2 above iron core 18.19
magnetic poles 20 to 23 extending perpendicularly from mutually opposing surfaces, and excitation coils 24 to 2 attached to the magnetic poles 20 to 23;
Consists of 7. At this time, the magnetic pole faces 20a to 23a of each of the magnetic poles 20 to 23 are 90 degrees from the direction in which the magnetic poles 20 to 23 extend from the magnetic pole mounting surface of the iron core 18.19 (located on the upper surface in the figure). stipulated in Teeth are formed on the surfaces of these magnetic pole faces 20a to 23a, and the pitch of each tooth is equal to the pitch of the secondary teeth, which will be described later. The teeth are arranged sequentially displaced by 1/4 pitch. 28 is a secondary scale, which maintains a constant gap G between the magnetic pole faces 20a to 23a and
The next side 1 constitutes a linear pulse motor, and the above magnetic pole surface 2
Tooth portions 28a having the same pitch as the tooth portions formed on the respective magnetic pole faces 20a to 23a are formed on the opposing surfaces of the magnetic pole faces 0a to 23a.

29 C is a bearing ball that rolls while maintaining a constant distance between the primary side as the linear pulse motor main body and the facing surface of each tooth portion of the scale 28, and also carries out the guiding action of the scale 28.

Further, the balls 29 are arranged at four locations on both sides of the iron core 1B and '190, and their transfer range is regulated by an A guide (not shown). It is determined to be twice.

Now that we have the configuration shown in FIGS. 3 to 5 above.

Each of the convex parts of the teeth formed on the magnetic pole surface 23a and the teeth 28a formed on the scale 28 obtains an attractive force as a result of the generation of magnetic flux that promotes the magnetic flux of the permanent magnet P2 as the excitation coil 27 is energized. When the excitation coil 27 is de-energized and the excitation coil 25 is simultaneously excited from the state (the state shown in FIG. 4), the teeth formed on the magnetic pole face 21a and the scale teeth 2
The magnetic flux of the permanent magnet P2 and the magnetic flux generated due to the excitation of the excitation coil 25 are added between each convex portion of the magnet 8a, and a strong magnetic attraction force is exerted, resulting in a large pitch displacement (- to fix the next side 17). In this case, the scale 24 is displaced to the left. Next, by sequentially exciting only the excitation coils 26 and 24, a displacement of 1/4 pitch is produced based on the same principle. By repeating the above operations, the linear pulse motor displaces the movable side by 1/4 pitch, thereby controlling the positioning of a controlled object (not shown) attached to the movable side.

During operation of this linear pulse motor, the total magnetic flux generated from the negative side magnetic flux generation source is distributed between the teeth formed on the magnetic pole faces 20a to 23a and the teeth 28a formed on the scale 28, as shown in FIGS. 3 to 5. With a direction change on the opposing surface, the liquid always flows into the scale 24 and then flows out from the scale.

In addition, in FIGS. 3 to 5 showing the embodiments of the present invention, a configuration is shown in which each magnetic pole is provided with an independent excitation coil, but by controlling the direction in which the current flows in the coil, the V
The number of excitation coils will be halved.

In addition, the exciting coils can be located on both sides, and various modifications are possible.

On the other hand, the excitation means of the excitation coil is not limited to the method of exciting one phase at a time as explained above, but can also be the well-known two-phase excitation, and can also be applied to reactance type linear pulse smoke that does not have a permanent magnet. can.

As described above, the linear pulse smoke according to the present invention is characterized by the direction in which the magnetic flux generated in the negative side main body passes through the magnetic pole, and the direction in which the magnetic flux passes between the magnetic pole surface and the tooth portion formed on the scale surface opposite thereto. The gist of this is that the arrangement is such that the direction in which it is used is perpendicular to the direction in which it is used. Based on this configuration, the conventional primary height H is the sum of the gap and scale thicknesses (determined by the length of the magnetic pole and the length of the coil winding), especially in low-thrust applications. On the other hand, the height of the linear pulse motor of this invention is determined by the sum of the thickness of the magnetic pole core, the gap, and the thickness of the bearing support frame. The thickness of the core of the magnetic pole can be reduced as the height increases. Furthermore, in contrast to the structure of Jukei, in which the magnetic pole surfaces are arranged continuously along the moving direction of the linear pulse motor, in the linear pulse motor according to the present invention, the magnetic pole surfaces are arranged within the magnetic poles. Since the magnetic flux is parallel to the magnetic flux passing through the linear pulse motor, it can be arranged in a concentrated manner, and accordingly, the length of the primary side of the linear pulse motor can be shortened.

Moreover, since the primary and secondary gap maintaining mechanisms can be carried out by small-diameter balls together with scale guides, there is no tendency to increase the length in the width direction compared to the prior art. For these reasons, linear pulse motors have the advantage of being able to be miniaturized to suit use in various office automation equipment with small thrusts and small strokes.

[Brief explanation of drawings]

1 and 2 are partially cutaway front and side views showing a conventional configuration, respectively, and FIGS. 3, 4, and 5 each show a specific configuration of a linear pulse smoke according to the present invention. FIG. 2 is a plan view, a front view, and a side view. 20 to 23...Magnetic poles 20a to 23a...Magnetic pole face 24, bone, scale 24a, @e Scale teeth Applicant Shinko Electric Co., Ltd. Agent Patent attorney Haruya Saito No. 1 Figure 4 Figure g

Claims (1)

[Claims] 1. A plurality of magnetic pole faces on the primary side facing the scale teeth,
Same pitch as the scale teeth above, and. Forming tooth portions having a deviation by a reciprocal pitch of the number of magnetic poles,
In a basic configuration in which either the -next side or the movable side of the scale is moved in steps by reciprocal pitches of the number of magnetic poles by aligning the teeth of each magnetic pole surface with the scale teeth in sequence for each input pulse, the -next side A linear pulse motor configured such that the direction in which the magnetic flux generated in the magnetic flux passes through the magnetic poles and the direction in which it passes through the magnetic pole tooth surface, the air gap, and the scale tooth surface facing the magnetic pole surface form a right angle.